308 win and ww748

[bedwards]

I have a new mould CTL 309-160-2R that is 172gr with w/w after check and lube. I checked my trusty Lyman 3rd edition and started at 32 gr w/w 748 and have loaded 5 rounds each up to 43gr I don't think I need to push the boolit much harder than that.
I got on the forum last night and read where you don't want to load 748 lite. :sad:
also, I noticed that Lyman has completely dropped 748 in their suggested loads in the lastest book. I thought 748 and the 308 were made for each other?? Is 32gr too light a starting load? Its not too late for me to pull the boolits, but I really hate to waste them.

BTW this is for a Winchester model70 short barrel carbine.

thanks in advance
be

[jlchucker]

I've loaded countless rounds of .308 in the past with 748 and never had a problem. I also use it quite a bit in 30-30. Some of my loading manuals are old--going back to the 1970's when I started handloading. 748 has been a favorite powder of mine since that time, and has pushed a lot of boolets out of 30-30, 35 Remington, and .308. I even used to use jacketed load data (bottom end of the published data) with good luck. Never found a problem.

[Rocky Raab]

I personally don't like to reduce ball powders much, nor do I like them with cast bullets. Doing both together just makes me kind of butt squirmy. Trepidacious is the big dollar word for it.

W748 and the 308 are a perfect match - with jacketed bullets and full-power loads.

For cast bullets, I'd be looking at a slowish flake powder like 2400 for mild loads, and a single-base extruded like 5744 or 4198 for a little more oomph. For top end loads, 3031 or 4895.

[Larry Gibson]

bedwards

The concern 'to load lite" stems from the danger of SEE, which is real. Ball powders are mostly harder to ignite because of the deterrent coatings on them to control the burning rate. The slower the powder the harder to ignite. Also many of the slower ball powders do not burn efficiently until they get within a certain pressure range which is usually higher than the peak pressure of most cast bullet loads. If not ignited properly misfires can occur along with hangfires. It is with hangfires when using these slow burning powders with the jacketed bullet getting stuck in the throat causing a bore obstruction under certain conditions that result in SEE (Secondary Explosive Effect). Most SEEs result in catastrophic failure to the firearm and probably injury to the shooter.

However, in most cases a cast bullet, even if it gets stuck in the throat, will soon get pushed out well before the pressure reaches SEE levels because of the softer nature of cast bullets vs the harder copper/steel jacket of a jacketed bullet.. I have heard of only one instance of SEE with a cast bullet but do not know the details. Therefore I can not say for certainty there is a danger of SEE with cast bullets.

In some cases like the 30-30 ball powders, especiall the medium burning rate powders, will work fine. In other cases where loading density is high and the cast bullets are heavy for caliber they also work fine even with slow burning powders. The biggest problem with the use of such ball powders with reduced loads with light and medium weight cast bullets in most cases is one of inconsistent ignition. The best way to know if it is working with your combination of 748 and the 172 gr cast bullet is to chronograph them as you test them. If your 5 shot strings do not produce an extreme spread (not standard deviation) of more than 75 fps at the low end of your tests and are within at least 50 fps at the higher end loads then you are getting good ignition. If the accuracy is good and the ES is 50 fps or less with that load then an additional test of 3 five shot groups or 1 ten shot group will tell you if it is a good load. One group of 5 shots during the test is only an indicator. The subsequent test will confirm whether it is a good load or not.

However, if the ES is not down to 50 fps or less with what appears to be the most accurate load then the ignition is not consistent and the accuracy will not be good. Accuracy will not be satisfying with any further experimenting if such is the case. It is then time to move on to a more readily igniteable medium burning powder of which there are many.

Let us know what you find in your tests.

Larry Gibson

[bedwards]

thanks guys

be

[OutHuntn84]

What a ka-winki-dink I just picked up the same mold and powder and was thinking about close to the same load. Looks like it might be a while before I actually load some up to test, but if you are already doing the R&D on it let me know how it goes.